Killer Filler - New Roof Insert

Most cars manufactured before the late ’30s were assembled with wooden roof inlays, mostly because factory presses were not yet able to stamp out a full-steel roof. The first Fords so equipped were ’36 models. Early body and roof supports were also made of wood and coated with pegamoid, a waterproof varnish.

2/22Here’s the initial test fit for the 18-gauge replacement panel, whose crown varies in the front and rear to match FoMoCo’s roof. It’s initially manufactured in two pieces but is delivered as a single, welded piece.

It didn’t take long for hot rodders to start filling in their rotting roofs. For many years, the simplest solution came from junkyards: Just find a ’50s or early ’60s station wagon that had about the right roof shape and crown, then cut it out to roughly fit your coupe or sedan’s roof opening. Typically, the new top piece overlapped the roof’s edges. After welding, a whole lot of Bondo was required to make the merger look decent—except in bright sunlight, which would reveal the edges right through the paint. We have much better ways today. Why not order a roof insert specially made for your car, giving you a closer fit from the start? The new top piece is butt-welded to the roof with no overlap anywhere. Once the welds are hammered out, there should be minimal distortion of the sheetmetal.

We were invited to Huntington Beach, California, to follow one such job by Roy Fjastad Jr. of West Coast Street Rods (WestCoastStreetRods.net; 714/841-5700). While our demonstrator happened to be a ’32 Ford Tudor, Roy assured us that the same methods apply to most ’30s cars with “open roofs.” Whereas the steel that Ford stamped into Deuces was 19-gauge, the closest thickness available today is 18-gauge. Roy orders the replacement panel in the correct shape and size from Walden Speed Shop (Pomona, California). Bobby Walden shapes the sheetmetal with a big Yoder Power Hammer to the correct crown for a specific car, ensuring a natural fit for that particular roof. He also rounds the corners of the fill piece, making welding easier.

Roy advises that welding should be done only with TIG or gas, because wire-feed units can produce a hard seam subject to cracking later. If you are a novice with the TIG torch, he recommends tack-welding in a few places, then turning the job over to a professional for final welding. Done properly, the end result is the smooth, solid, termite-proof top Detroit never delivered.

3/221 Roy Fjasted Jr. fabricated these small sheetmetal pieces for holding the new roof insert in place with Cleco clips. Each is numbered to match a drilled hole in the roof

4/222 The Cleco tool originated in the aircraft industry, quickly found favor with chassis shops, and has trickled down to home builders who always seem to be discovering new uses for the clever device. The spring-loaded clips come in various lengths.

5/223 The original roof won’t be drilled until the replacement panel’s edges are trimmed to roughly fit the opening.

6/224 Roy removed, test-fit, and trimmed the insert multiple times to get the gap as tight as possible. Once he was happy with the edging, he drilled the roof for the outer row of Clecos.

7/225 Roy (right) and a helper removed the insert for fine trimming of the roof edges.

8/226 Moving to the body, Roy used a sharp tin snip for trimming these roof edges. Sometimes, a file and/or a small grinder also participate.

9/227 Here’s the final fit after the roof was fine-trimmed to precisely fit the insert. Roy explained that the thinnest possible gap results in the best welds.

10/228 Roy started tack-welding in the middle of the longest part of the insert.

11/229 Each tack weld is hammered out with a dolly beneath the weld. Had Roy used the original roof edge and simply welded the insert on top, he could not have gotten to the edge to straighten it after welding because the two pieces of sheetmetal would’ve been stacked.

12/2210 After the first round of tack welds is complete, Roy starts the next set in between the first welds.

13/2211 Following two laps around the roof gap, Roy applied short tack welds between the existing welds. The idea is to avoid overheating the sheetmetal and prevent the panel from losing its shape.

14/2212 After many hours of welding and hammer-straightening, the end is finally near.

15/2213 Each and every weld is flattened with a body hammer and dolly before Roy resumes welding.

16/2214 Welding is completed. The next challenge is grinding it to make the roof smooth.

17/2215 A bigger grinder might save time and effort, but you have to be careful not to put much pressure on the sheetmetal, which can heat up and distort.

18/2216 Following one final round of fine grinding, Roy will break out the Bondo to correct the inevitable distortion caused by welding.

19/2217 Normally, this would be the final stage. In this case, Roy would do a bit more finish work because he’s doing a complete build for the customer.

20/2218 A thin coat of body filler was sanded down with 40-grit paper.

21/2219 Finally content with the new roof, Roy masked it off and sprayed a couple of coats of protective primer. The entire bare-metal body had previously been coated with metal prep to prevent rusting—standard procedure for incoming projects, due to this shop’s close proximity to the Pacific Ocean.

22/2220 Finally content with the new roof, Roy masked it off and sprayed a couple of coats of protective primer. The entire bare-metal body had previously been coated with metal prep to prevent rusting—standard procedure for incoming projects, due to this shop’s close proximity to the Pacific Ocean.